Many couples are considering other gemstones instead of diamonds. The most precious colored stones are sapphires, rubies, and emeralds. They are typically the alternative stone option for engagement rings. Sapphires and rubies are a good choice because they are very hard stones. Sapphires, typically blue, come in all colors except for red which is a ruby. They are a very popular option for an engagement ring due to Princess Diana’s famous ring. Rubies were traditional in Europe before diamonds, and emeralds are far more rare than diamonds. Other stones that are unique and wear-resistant are: chrysoberyl, topaz, and spinel. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity is another characteristic that lends value to a gemstone.
Mohs scale of mineral hardness: is a qualitative ordinal scale characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material.
Most of the stones below 7 are not suitable for engagement rings as they will wear down and scratch with everyday use.
|5||apatite , obsidian (volcanic glass)|
|6||Orthoclase, nephrite jade|
|6–7||Opal (5 – 61/2), peridot, tanzanite, jadeite jade|
|7||Quartz, some garnets, tourmalines|
|7.5–8||Beryl (emerald, green beryl, morganite, aquamarine, heliodor), spinel, some garnets|
|8.5||Chrysoberyl (alexandrite, chrysoberyl cat eyes, and colored chrysoberyl)|
|9||Corundum (sapphires and ruby)|